CRM WebUI has a standard feature of "Address proposal " in sales order/transaction level.This feature allow to change address for partner at sales order in case partner has multiple address using this button (address proposal in parties involved AB , refer attached screenshot) user can select the required address and save .

The sale order when replicates to SAP ECC the change address is not replicated hence at CRM level we have a changed new address for partner but in ECC sales order partner still hold the old address as the replication failed here in this case .

Can anyone provide any input on this as "address proposal " is a standard feature which SAP provides to have new address entered manually at the sales order/transaction level .

This should ideally replicate to connect SAP ECC system via middle ware as mostly CRM works with integration to SAP ECC and hence there should be middle ware replication also happening in this case .